WRX_Rich

iTrader: (5)

is it worth replacing the heads or getting them flowed

currently running a 02 wrx runing 386 bhp with
rcm gt35 p18 turbo
std internals
rcm manifold
rcm induction
aps front mount
etc

current wish list for this winter

Omega pistons.
Set of rings.
Arrow rods
Existing crankshaft
New main and big end brgs
RCM oil pump
14mm/12mm stud conversion
Bore check


i am going to have to pay for the install as its way above my level so money is running out rapidly

for the above list what do you reckon i do with the heads?

is it possible to add newage spec c heads or does the vvt stop this?

or would a port and polish be needed, i don't really have the money but if its worth doing

we can read loads of the advantages \ dissadvantages for 2, 2.2 , 2.3 and 2.5 bottom ends but i never see much about head work

thinking future I don't think i would be changing turbo, may be adding a p20 housing but currently not going to risk the extra lag

as always all help welcome along with any thoughts on my current wish list

Rich

DesR

Hi

Im running well over 400 on UK heads with only a port and a polish.

Cheers

Neilo

as standard they seem to be a bit of a restrction on mine and i cant seem to get much over 400 with them.....as above a good port and polish may sort that out though.

scoobysmiff

iTrader: (2)

i ported and polished mine myself, not done Bhp on it yet coz i'm not finished, wasn't too hard tbh, just didn't take too much out but was more of a blend really, the valve seats do not blend into the port very well at all so i smoothed all that out, also matched the ports to the gaskets and then to the inlet manifold as well, easily done i thought

WRX_Rich

iTrader: (5)

Nelio

it has been your current posts that has driven these questions

still happy with the 2.5 ?

ive been so impressed with the current spec, current thoughts are to stick with my 2 litre just to make it last

WRX_Rich

iTrader: (5)

so current opinion is port & polish is worth the money

Neilo

Hi rich,

yeah im still perfectly happy with the 2.5, im just trying to get more out of this turbo and hopefully the headswap will do just that (along with the 3" inlet from the other post)

fingers crossed

WRX_Rich

iTrader: (5)

Neil will this be your 3rd turbo change in a year?

you wont be happy till you go twisted, why put of the inevitable

i still haven't ruled out a 2.5 but watching your progress I do realise its not as simple as bolting my heads to a new bottom end and driving off - like some tuners (non scoobynet) would have lead me to believe this time last year

Neilo

no no, same turbo, just converting the cover....

twisted is another year i think.....i know what i want for the spec this year, and i want to keep it the same througout so that im 100% used to the car in all conditions.

Technically it is that simple, but in order to get the best out of it, then no, there is more to it.

At some point ill post some of my RR graphs, but at the end of the day, if you believe them....then i am about 35bhp down on you anyway! so why bother!

My main concern is that power and torque more importantly drops off too quickly for my liking. Am hoping that converting it to 3" and getting some proper heads on there will eliminate that to a certain degree, if not completely....i cant believe that the turbos running out of puff at 6k to be honest....

WRX_Rich

iTrader: (5)

Neil

I have always watched the progress of your car as i have always been a couple of steps behind, your posts have always been useful -l you should start a project thread for those who have not been able to see you car develop

as for power figures i bet the area under the line on yours speaks words, your 1/4 mile times proove this

have you thought about spec c heads rather than sti 5 ?

out of interest have we got simualr turbos ?

Neilo

Thanks

I do keep meaning to do a project thread, i may very well do one today as it will be something to to kill an afternoon in the beginning......

Im not sure that your behind me by any means, it sounds like youve got a very well set up car....i certainly wouldnt be uphappy with that. Although im guessing that yours potentially doesnt get the abuse that mine does, maybe im wrong.

I havent actually 1/4'd the car in this spec, it was something that i wanted to do a couple of months back but something came up so i couldnt....i will be doing it next year though but by then, more woudl have changed and hopefully i will have the vast majority of the package in place. (would be hoping for a high 11 though on that front)

The turbos are quite different id suggest, and im not overly sure how they differ powerwise so much, but from my understanding yours is a GT35 with a P18. Mine is a slightly older design GT30 core with a larger exhaust housing probably a bit bigger than a P20, which would suggest to me that it should make some fairly good numbers, but as yet (despite how it feels on the road which is relatively strong) doesnt hit them on the rollers, but thats fine, i expect that. Id be interested to know if your car hits peak boost on your RR printout of 386 and i would suggest that my car when on the road is probably hitting a similar number, but on the rollers it struggles to get within 0.2bar of peak.

Spec C heads would be more hassle thats its worth, mainly due to having to shut off the AVCS (more work and more money) and arguably the STI5 cams are still potentially superior (i stand to be corrected) just that any difference is negated by the use of AVCS on the spec C ones.

WRX_Rich

iTrader: (5)

up for Friday night

give me something to read wehn i come back from the pub